C Programming Questions and Answers

What will be the output of the following program :

#include<stdio.h>
main()
{
	int a=555,b=*ptr,*ptr=&a;
        printf("%d %d %d",++a,--b,*ptr++);
}

What will be the output of the following program :

#include<stdio.h>void main()
{
	float val=5.75;
	  int *ptr=&val;
	  printf("%.2f %.2f",*(float *)ptr,val);
}

What will be the output of the following program :

#include<stdio.h>
main()
{
	int a=5u,*b,**c,***d,****e;
	  b=&a;
	  c=&b;
	  d=&c;
	  e=&d;
	  printf("%u %u %u %u",*b-5,**c-11,***d-6,65535+****e);
}

What will be the output of the following program :

#include<stdio.h>void main()
{
	int (*a)[5];
	printf("%d %d",sizeof(*a),sizeof(a));
}

What will be output of following program?

#include<stdio.h>#include<string.h>int main()
{
    int register a;
    scanf("%d",&a);  // say a = 10
    printf("%d",a);
    return0;
}

What will be the output of the following program :

#include<stdio.h>
main()
{
	int val=1234;
	int* ptr=&val;
	printf("%d %d",val,*ptr++);
}

In which header file is the NULL macro defined?

What will be output of following program?

#include<stdio.h>#include<string.h>int main()
{
    int a,b,c,d;
    char *p = (char*)0;
    int *q = (int*q)0;
    float *r = (float*)0;
    double *s = 0;
    a = ( int)(p+1);
    b = ( int)(q+1);
    c = ( int)(r+1);
    d = ( int)(s+1);
    printf("%d %d %d %d",a,b,c,d);
    return0;
}

What will be output of following program?

#include<stdio.h>#include<string.h>int main()
{
    int a,b,c,d;
    char *p = (char*)0;
    int *q = (int*q)0;
    float *r = (float*)0;
    double *s = 0;
    a = ( int)(p+1);
    b = ( int)(q+1);
    c = ( int)(r+1);
    d = ( int)(s+1);
    printf("%d %d %d %d",a,b,c,d);
    return0;
}

What will be the output of the following program :

#include<stdio.h>
main()
{
	int val=1234;
	int* ptr=&val;
	printf("%d %d",++val,*ptr);
}